Method of adding fats and oils to porous fodder

Abstract

A method of adding oil and fat to porous feed is disclosed wherein porous feed together with oil and fat are continuously inserted into a partially evacuated chamber of an oil and fat adding apparatus while, simultaneously, porous feed that has remained therein for a specified time is continuously being removed from the chamber. The continuous nature of this method allows porous feed having high fat and oil content to be produced more rapidly than previously possible.

What is claimed is:  
     
       1. A method for adding fat and oil to porous feed comprising: 
       providing porous feed directly from an extruder to a drier;  
       drying the porous feed by heated air in the drier;  
       inserting the dried and heated porous feed together with the fat and oil into a chamber of a fat and oil adding apparatus, wherein the dried and heated porous feed is inserted directly therein from the drier such that the dried and heated porous feed substantially maintains the temperature it possesses upon exit from the drier, there being a partial vacuum in the chamber of the fat and oil addiing apparatus and the inserting of both the porous feed and the fat and oil being performed in a continuous manner such that additional porous feed and fat and oil are constantly being inserted into the chamber of the fat and oil adding apparatus;  
       keeping the porous feed and the fat and oil in the fat and oil adding apparatus for a specified time; and  
       removing the porous feed from the chamber of the fat and oil adding apparatus after the specified time has elapsed, the removal of the porous feed being performed in a continuous manner such that porous feed is constantly being removed from the chamber of the fat and oil adding apparatus while additional porous feed and additional fat and oil are being inserted therein.  
     
     
       2. A method for adding fat and oil to porous feed according to  claim 1 , wherein the chamber of the fat and oil adding apparatus has first and second opposite ends and the fat and oil adding apparatus is an apparatus comprising a pair of rotary valves and a ribbon screw, one of the pair of rotary valves being positioned at the first end of the chamber and the other of the pair of the rotary valves being positioned at the second end of the chamber, the rotary valves maintaining the partial vacuum within the chamber while allowing the insertion and the removal of the porous feed from the chamber, the ribbon screw having an axis that extends between the first and second ends of the chamber and being pivotally mounted in the chamber for rotation about its axis, the ribbon screw also having a helical blade that winds about the axis of the ribbon screw in a manner such that the blade of the ribbon screw stirs and moves the porous feed from one of the first and second ends of the chamber to the other when the ribbon screw is revolved about its axis. 
     
     
       3. A method for adding fat and oil to porous feed according to  claim 2 , wherein the partial vacuum of the chamber of the fat and oil adding apparatus is from −400 to −700 mmHg. 
     
     
       4. A method for adding fat and oil to porous feed according to  claim 3 , wherein fat and oil are added so that the fat and oil content of said porous feed is from 20 to 30% in terms of weight ratio. 
     
     
       5. A method for adding fat and oil to porous feed according to  claim 2 , wherein fat and oil are added so that the fat and oil content of said porous feed is from 20 to 30% in terms of weight ratio. 
     
     
       6. A method for adding fat and oil to porous feed according to  claim 2 , wherein decompression and return to normal pressure of said porous feed by said fat and oil adding apparatus are repeated multiple times. 
     
     
       7. A method for adding fat and oil to porous feed according to  claim 1 , wherein the partial vacuum of the chamber of the fat and oil adding apparatus is from −400 to −700 mmHg. 
     
     
       8. A method for adding fat and oil to porous feed according to  claim 7 , wherein fat and oil are added so that the fat and oil content of said porous feed is from 20 to 30% in terms of weight ratio. 
     
     
       9. A method for adding fat and oil to porous feed according to  claim 7 , wherein decompression and return to normal pressure of said porous feed by said fat and oil adding apparatus are repeated multiple times. 
     
     
       10. A method for adding fat and oil to porous feed according to  claim 1  wherein fat and oil are added so that the fat and oil content of said porous feed is from 20 to 30% in terms of weight ratio. 
     
     
       11. A method for adding fat and oil to porous feed according to  claim 10 , wherein decompression and return to normal pressure of said porous feed by said fat and oil adding apparatus are repeated multiple times. 
     
     
       12. A method for adding fat and oil to porous feed according to  claim 1 , wherein decompression and return to normal pressure of said porous feed by said fat and oil adding apparatus are repeated multiple times. 
     
     
       13. A method for adding fat and oil to porous feed according to  claim 1 , further comprising the step of cooling the porous feed after removing the porous feed from the chamber of the fat and oil adding apparatus. 
     
     
       14. A method for adding fat and oil to porous feed according to  claim 13 , wherein the partial vacuum of the chamber of the fat and oil adding apparatus is from −400 to −700 mmHg. 
     
     
       15. A method for adding fat and oil to porous feed according to  claim 14 , wherein fat and oil are added so that the fat and oil content of said porous feed is from 20 to 30% in terms of weight ratio. 
     
     
       16. A method for adding fat and oil to porous feed according to  claim 13 , wherein decompression and return to normal pressure of said porous feed by said fat and oil adding apparatus are repeated multiple times. 
     
     
       17. A method for adding fat and oil to porous feed according to  claim 13 , wherein the chamber of the fat and oil adding apparatus has first and second opposite ends and the fat and oil adding apparatus is an apparatus comprising a pair of rotary valves and a ribbon screw, one of the pair of rotary valves being positioned at the first end of the chamber and the other of the pair of the rotary valves being positioned at the second end of the chamber, the rotary valves maintaining the partial vacuum within the chamber while allowing the insertion and the removal of the porous feed from the chamber, the ribbon screw having an axis that extends between the first and second ends of the chamber and being pivotally mounted in the chamber for rotation about its axis, the ribbon screw also having a helical blade that winds about the axis of the ribbon screw in a manner such that the blade of the ribbon screw stirs and moves the porous feed from one of the first and second ends of the chamber to the other when the ribbon screw is revolved about its axis. 
     
     
       18. A method for adding fat and oil to porous feed according to  claim 17 , wherein the partial vacuum of the chamber of the fat and oil adding apparatus is from −400 to −700 mmHg. 
     
     
       19. A method for adding fat and oil to porous feed according to  claim 18 , wherein fat and oil are added so that the fat and oil content of said porous feed is from 20 to 30% in terms of weight ratio. 
     
     
       20. The method of  claim 1  wherein the drying step includes drying the porous feed by heated air in the drier such that, upon exit therefrom, the porous feed possesses a temperature in a range of approximately 70 degrees Celsius to approximately 100 degrees Celsius.